Dental handpiece

ABSTRACT

An improved micromotor-driven dental handpiece consists of a cylindrical body which includes an inner sleeve and an outer sleeve slidingly fitting over the inner sleeve, the two sleeves being maintained axially relative to each other. A detent slidingly mounted on the outer sleeve releasably interconnects it with a gripper-locking sleeve and concurrently actuates a mechanism by means of which the shaft of the handpiece may be intercoupled with the inner sleeve, whereupon the locking or releasing of the cutting tool is effected by turning the outer and inner sleeve relatively to each other.

United States Patent 1 Seigneurin 1 June 6, 1972 54] DENTAL HANDPIECE 2,053,056 9/1936 Whiteside ..32/D1G. 8

3,210,847 10/1965 Prufer.... ..32/27 [72] Invent Mchel se'gneurm Besancm 3,448,309 6/1969 Epp ..310/51 [73] Assignee: Micro-Mega S.A., Besancon, France 3,509,629 5/1970 Kidokoro et a1 ..32/27 [22] Filed: Aug. 29, 1969 Appl. No.: 854,140

Primary Examiner-Robert Peshock AttorneyRobert E. Burns and Emmanuel J. Lobato 5 7] ABSTRACT An improved micrometer-driven dental handpiece consists of a cylindrical body which includes an inner sleeve and an outer sleeve slidingly fitting over the inner sleeve, the two sleeves being maintained axially relative to each other.

A detent slidingly mounted on the outer sleeve releasably interconnects it with a gripper-locking sleeve and concurrently actuates a mechanism by means of which the shaft of the handpiece may be intercoupled with the inner sleeve, whereupon the locking or releasing of the cutting tool is efiected by turning the outer and inner sleeve relatively to each other.

9 Claims, 2 Drawing Figures PATENTEDJUH 61972 3,667, 125

SHEET 10F 2 FIG] DENTAL HANDPIECE This invention relates to handpieces used in surgical and dental work. More particularly it relates to handpieces powered by micromotors.

It is an object of the invention to provide a handpiece which is suitable for assembly with any type of micromotor while providing convenient means for opening or closing the tool chuck.

In accordance with the invention this is achieved by a handpiece characterized in that the cutter may be locked in place or released by the displacement of a mobile member slidingly mounted on the body of the handpiece, and by subsequent rotation of said body relatively to the shaft of the handpiece.

More particularly, in accordance with the invention the body of the handpiece comprises a first outer sleeve in which is slidingly inserted a second inner sleeve and a movable member slidingly mounted onto said outer sleeve, said movable member carrying a projection which, when the moving member is pushed in the longitudinal direction, engages toothlike projections on a locking sleeve and at same time intercouples by means of a toothed sliding body the inner sleeve with the shaft of the handpiece.

For a better understanding of the invention reference will now be made to the following description given by way of example and the accompanying drawings in which FIG. 1 is a longitudinal sectional view of the handpiece according to the invention.

FIG. 2 is a perspective view of the shaft, locking sleeve and sliding piece shown in FIG. 1. 7

As shown in the drawings, the handpiece 1 includes an inner sleeve 3 which slidingly fits into an outer sleeve 2. The relative position of the sleeves with respect to each other in the longitudinal direction is maintained by a locking mechanism such as shown at 4. The mechanism consists of a bent spring engaging two grooves in registry, of which one is formed on the inner wall of sleeve 2 and the other on the outer wall of sleeve 3.

The groove on the inner wall of sleeve 2 has an opening 5 extending therethrough. By inserting a suitable tool into the opening the spring may be pushed inward, thereby disengaging the two sleeves and enabling the outer sleeve 2 to slide on the inner sleeve 3.

The handpiece is suitable for hooking onto all types of micromotors and onto a wrist-joint by means of any fastening device 6 for example as disclosed in French Pat. No. 1,483,766 ofFeb. 7, 1966.

In the center of the sleeve 3 there is mounted a bearing 7 which supports the shaft 8 of the handpiece. The shaft 8 is coupled to the shaft of the motor by a screw type coupling arrangement 25 and is driven by the motor.

At the other end the shaft 8 has a threaded portion 9 onto which is screwed a locking sleeve 10. The sleeve 10 terminates in a conventional conical portion 11 and serves to lock or release the cutter (not shown) inserted therein by a displacement in the axial direction.

The locking sleeve 10 is rotatably supported by a bearing 1 I. and has its rear end formed with castellations or teeth 12. These teeth cooperate with the lower end of a screw 13 which rigidly interconnects an inner sliding ring 14 with a pushing member or detent l5 slidably mounted on the sleeve 2 and capable of movement within a slot 21.

When the detent 15 is moved backward in the direction of arrow F, the end of the screw 13 engages the teeth 12 and intercouples rotation-wise the locking sleeve 10 with the outer sleeve 2. Concurrently, the ring 14, being rigidly secured to the detent l5, drives back a cylindrical sliding body 16 which on the one hand is provided with circumferential projections 17 on its lateral surface and on the other hand with axially extending teeth 18.

As the body 16 moves backward, its projections 17 engage corresponding axial recesses 19 formed at the end of the inner sleeve 3, while its teeth 18 come into engagement with teeth 20 on shaft 8.

Thus, by moving the detent 15 backward within the slot 21 the outer sleeve 2 becomes intercoupled rotation-wise with the locking sleeve 10 and, by the action of the sliding body 16, the shaft 8 becomes coupled with the inner sleeve 3. Once this is achieved, locking or releasing of the tool may be effected by turning the sleeves 2 and 3 relative to each other, thereby imparting a transversal movement to the locking sleeve 10. Depending on the direction in which the locking sleeve turns. it will either tighten or loosen the cutter inserted into the gripper 22. l

A spring 23 interposed between the bearing 7 and the sliding body 16 serves to return the latter, as well as the ring 14 and detent 15, to their original position, when the detent 15 is released whereby the handpiece 1 is again ready for use.

It will be appreciated that the invention lends itself to many variations. Thus, the teeth 18 on the sliding piece 16 may be omitted altogether and the piece may be intercoupled with the shaft 8 by means of grooves in said shaft.

This and other modifications of form and arrangement clearly remain with the scope and spirit of the invention. As another example, the holder 22 may be designed either for long cutters such as normally used with handpieces or else be adapted to hold a short cutter having an offset angle.

What is claimed is:

1. In a dental handpiece for connection to a micromotor, a casing comprising a normally stationary outer casing sleeve providing a hand grip for the handpiece and an inner casing sleeve rotatably disposed partly in said outer casing sleeve and having a portion extending beyond an end of said outer casing sleeve, a shaft rotatably supported in said inner casing sleeve for rotation relative to both of said casing sleeves, means for releasably connecting said casing to a micromotor having a rotor, means for coupling one end of said shaft to the rotor of said micromotor for rotation inside said casing, means at the other end of said shaft for holding a tool, said tool holding means comprising a locking sleeve rotatable relative to said shaft in one direction to secure a tool and in the opposite direction to release a tool, and means operable from outside said casing for temporarily connecting said locking sleeve for rotation with one of said casing sleeve and at the same time for temporarily connecting said shaft for rotation with the other of said casing sleeves, whereby said locking sleeve and said shaft are rotatable relative to one another to secure or release a tool by manual rotation of said inner casing sleeve relative to said outer casing sleeve.

2. A dental handpiece according to claim I, in which said temporary connecting means comprises teeth on said locking sleeve, detent means on the outside of said outer casing sleeve movable axially of said outer casing sleeve, and a pin extending inwardly from said detent means in position to engage said teeth on said locking sleeve when said detent means is moved axially of said outer casing sleeve to connect said locking sleeve for rotation with said outer casing sleeve.

3. A dental handpiece according to claim 1, in which said temporary connecting means comprises a connecting sleeve inside said outer casing sleeve and cooperating means on said shaft and said inner casing sleeve, said connecting sleeve being movable axially between a position in which it connects said shaft for rotation with said inner casing sleeve and a position in which said shaft and inner casing are disconnected.

4. A dental handpiece according to claim 2, comprising spring means for biasing said connecting sleeve to a position in which said shaft and said inner casing sleeve are disconnected.

5. A dental handpiece according to claim 2, in which said inner casing sleeve and said shaft are provided with teeth and in which said connecting sleeve has teeth engageable with said teeth of said shaft and said inner casing sleeve when said connecting sleeve is moved axially to a position for connecting said shaft and inner casing sleeve.

6. A dental handpiece according to claim 2, in which said temporary connecting means comprises a connecting sleeve inside said outer casing sleeve and cooperating means on said shaft and said inner casing sleeve, said connecting sleeve being movable axially between a connecting position in which it connects said shaft for rotation with said inner casing sleeve and a released position in which said shaft and inner casing sleeve are disconnected, and means associated with said detent means for moving said connecting sleeve from released to connecting positions when said detent means is moved axially to connect said locking sleeve for rotation with said outer casing sleeve.

7. A dental handpiece according to claim 6, in which said means associated with said detent means comprises an inner sliding ring slidable axially inside said outer casing sleeve and connected to said detent means.

8. A dental handpiece according to claim 1, in which said outer casing sleeve has an inner circumferential groove and said inner casing sleeve has an outer circumferential groove registering with said groove of said outer casing sleeve and in which a locking spring disposed in said grooves connects said inner and outer casing sleeves to lock them against relative axial movement while permitting relative rotation.

9. A dental handpiece according to claim 8, in which said outer casing has a hole opening into said groove for insertion of an instrument for engagement with said locking spring to depress said spring and thereby release said outer casing sleeve from said inner casing sleeve. 

1. In a dental handpiece for connection to a micromotor, a casing comprising a normally stationary outer casing sleeve providing a hand grip for the handpiece and an inner casing sleeve rotatably disposed partly in said outer casing sleeve and having a portion extending beyond an end of said outer casing sleeve, a shaft rotatably supported in said inner casing sleeve for rotation relative to both of said casing sleeves, means for releasably connecting said casing to a micromotor having a rotor, means for coupling one end of said shaft to the rotor of said micromotor for rotation inside said casing, means at the other end of said shaft for holding a tool, said tool holding means comprising a locking sleeve rotatable relative to said shaft in one direction to secure a tool and in the opposite direction to release a tool, and means operable from outside said casing for temporarily connecting said locking sleeve for rotation with one of said casing sleeve and at the same time for temporarily connecting said shaft for rotation with the other of said casing sleeves, whereby said locking sleeve and said shaft are rotatable relative to one another to secure or release a tool by manual rotation of said inner casing sleeve relative to said outer casing sleeve.
 2. A dental handpiece according to claim 1, in which said temporary connecting means comprises teeth on said locking sleeve, detent means on the outside of said outer casing sleeve movable axially of said outer casing sleeve, and a pin extending Inwardly from said detent means in position to engage said teeth on said locking sleeve when said detent means is moved axially of said outer casing sleeve to connect said locking sleeve for rotation with said outer casing sleeve.
 3. A dental handpiece according to claim 1, in which said temporary connecting means comprises a connecting sleeve inside said outer casing sleeve and cooperating means on said shaft and said inner casing sleeve, said connecting sleeve being movable axially between a position in which it connects said shaft for rotation with said inner casing sleeve and a position in which said shaft and inner casing are disconnected.
 4. A dental handpiece according to claim 2, comprising spring means for biasing said connecting sleeve to a position in which said shaft and said inner casing sleeve are disconnected.
 5. A dental handpiece according to claim 2, in which said inner casing sleeve and said shaft are provided with teeth and in which said connecting sleeve has teeth engageable with said teeth of said shaft and said inner casing sleeve when said connecting sleeve is moved axially to a position for connecting said shaft and inner casing sleeve.
 6. A dental handpiece according to claim 2, in which said temporary connecting means comprises a connecting sleeve inside said outer casing sleeve and cooperating means on said shaft and said inner casing sleeve, said connecting sleeve being movable axially between a connecting position in which it connects said shaft for rotation with said inner casing sleeve and a released position in which said shaft and inner casing sleeve are disconnected, and means associated with said detent means for moving said connecting sleeve from released to connecting positions when said detent means is moved axially to connect said locking sleeve for rotation with said outer casing sleeve.
 7. A dental handpiece according to claim 6, in which said means associated with said detent means comprises an inner sliding ring slidable axially inside said outer casing sleeve and connected to said detent means.
 8. A dental handpiece according to claim 1, in which said outer casing sleeve has an inner circumferential groove and said inner casing sleeve has an outer circumferential groove registering with said groove of said outer casing sleeve and in which a locking spring disposed in said grooves connects said inner and outer casing sleeves to lock them against relative axial movement while permitting relative rotation.
 9. A dental handpiece according to claim 8, in which said outer casing has a hole opening into said groove for insertion of an instrument for engagement with said locking spring to depress said spring and thereby release said outer casing sleeve from said inner casing sleeve. 